I test both firefox and IE with the Panda EICAR Virus and webshield nor Standard Shield did not detect it. I made sure my javascript is enable and all that and yet avast! didn’t detect the eicar testing virus.
http://www.pandasoftware.com/virus_info/work/
Webshield is still scanning webpages and Standard Shield works fine, just didn’t detect anything.
Well i can’t seem to even find the EICAR sample…
Use this link instead:
http://www.eicar.org/anti_virus_test_file.htm
This is the official EICAR test sample webpage.
Okay avast! is working perfectly after I went to this topic and the EICAR Program you gave me:
http://forum.avast.com/index.php?topic=12153.0
Panda on the other hand might be suffering from some sort of problem. Avast! webshield can detect the eicar virus perfectly. 
In my case AVAST Web Shield cannot detect Eicar Test File in eicarcom.zip and eicarcom2.zip in the download area using the secure, SSL enabled protocol https!?
Thats normal because Standard Shield doesn’t check inside archives (only when files are extracted) and Web Shield cannot scan secure connection.
Nothing to worry about.